since this guy 'Linksys WAG54G' will connect to your ISP, you do not need to do the adsl-start in linux at all.
The linksys box will handle the adsl connection
Look at the manual of Linksys WAG54G. See chapter 5? You can configure the linksys box by accessing the web inteface of the box.
The box has a default ip of 192.168.1.1. Login is admin
and password is admin
Now. In order to access the box's web interface, your NIC card must have the right ip address.
Can you try
? What did you see?
Assuming that your DLink NIC card is eth0. If eth0 has an IP similar to 192.168.1.x (where 2 <= x < 255) , then you can try out step 2 as mentioned above.
If not, post the result of step 3 and I'll get back to you.